Distribution Law And Experimental Study Of Heat Field Of New High-Speed Motorized Spindle Bearing-Spindle Core

The high-speed electric spindle is a key component in the machine tool system.Its performance directly affects the machining accuracy of the entire machine tool,so it has high requirements for the electric spindle and its components.Because the high-speed electric spindle is compact and the internal space is closed,the heat generation of the motor and the bearing is unavoidable,which causes the angular contact ball bearing and the shaft core to generate a temperature gradient,which causes thermal deformation and affects the stability and reliability of the electric spindle.At present,the high-speed electric spindle is greatly affected by thermal deformation during the further promotion process.It provides a theoretical basis for studying the thermal field distribution law of the electric spindle.The thermal field and deformation of the high-speed electric spindle bearing-axis core are deeply studied.Based on the detailed analysis of the lubrication and cooling system and the corresponding calculation of the supporting facilities,this paper analyzes the two major heat sources of the high-speed electric spindle-the motor heat generation and the friction heat generation of the hybrid ceramic ball bearing,and obtains the motor stator and rotor,and the angular contact.The heat transfer rate of the inner and outer rings of the ball bearing and the rolling element is discussed.The maximum contact stress and maximum deformation of angular contact ball bearings were calculated by Hertz contact theory.The nonlinear contact problems were simulated by ANSYS Workbench.The correctness of the finite element contact simulation was verified by comparing the simulation results with the calculated results.On this basis,the bearing steady temperature thermal analysis is carried out to obtain the bearing temperature field,and the thermal-stress coupling analysis of the bearing is further carried out.The deformation of the bearing and the distribution of the bearing temperature field under the coupled field are obtained.The internal heat transfer coefficient of the high-speed electric spindle is calculated,and the thermal field distribution law of the electric spindle and the thermal field distribution law and thermal deformation of the shaft core are obtained.The problem of improving the heating and deformation of the shaft core from heat source,heat dissipation and compensation is proposed.The influence law of the oil and gas lubrication system on the shaft core heating is obtained.At the end of this paper,an experimental platform for temperature rise and axial deformation of high-speed electric spindle is built.The front end surface temperature and axial axial deformation of the electric spindle are measured under no-load and constant speed conditions.It is found that the deviation between the experimental data and the simulation analysis is within the allowable error,thus confirming that the theoretical method of this paper is feasible.In this paper,the research method of high-speed electric spindle bearing-axis core thermal field is proposed,which provides a corresponding theoretical basis for the replacement of electric spindle,which is of great significance for the development of higher precision electric spindle.